Adaptability to the attack & to internal weaknesses
One more key difference between biometric authentication and any other authentication technic.
Facing the progress of attack technic, any algorithm can be improved by enlarging the size of the field to attack through brute force. For example algorithms where strength is proportionnal to one key size may be strengthened by publicly announcing that from now on key sizes lower than N bits are prohibited.
Facing the discovery of internal weaknesses within given algorithms, this information can be published and the option to use these weaker algorithms may be officially prohibited.
No such freedom exists with biometric technics.
You can't enlarge the variability of your iris pattern, even with a very large brain and some exceptionnal will.
You can't either change it if you discover that within your family there is a default within your genetic code causing a huge number of similitudes within your iris patterns.
Biometric technics can't adapt to:
- progress of the attack
- bias in their probability distribution
With such deffects, in a real world, these technics shouldn't survive.
In horror films (minority report) they have a duly deserved success.